Scala Cookbook

Introduction

Scala is both an object-oriented programming (OOP) and a functional programming (FP) language. This chapter demonstrates functional programming techniques, including the ability to define functions and pass them around as instances. Just like you create a String instance in Java and pass it around, you can define a function as a variable and pass it around. I’ll demonstrate many examples and advantages of this capability in this chapter.

As a language that supports functional programming, Scala encourages an expression-oriented programming (EOP) model. Simply put, in EOP, every statement (expression) yields a value. This paradigm can be as obvious as an if/else statement returning a value:

val greater = if (a > b) a else b

It can also be as surprising as a try/catch statement returning a value:

val result = try {
  aString.toInt
} catch {
  case _ => 0
}

Although EOP is casually demonstrated in many examples in this book, it’s helpful to be consciously aware of this way of thinking in the recipes that follow.